A few months back I asked about flickering low energy bulbs when they are
switched off and I was pointed to this:
In exceptional cases a CFL will flash occasionally when switched off. This
is due to wiring capacitance passing a tiny current, which gradually charges
the CFL's reservoir capacitor, and after a while it attmpts to start, giving
a momentary flicker.
2 conditions tend to cause this:
a.. an especially long switch wire run
b.. supply switched on the neutral instead of live pole
The question is, is the energy being consumed when the lights supposed to be
off costing me money, ie is it clocking up on my electricity meter. If I am
getting this for nothing fair enough but if I am paying for it what is the
point of a low energy bulb that consumes energy when it is switched off. In
my case it is a constant flicker on three lights that have an light
sensitive security switch.
Better things to worry about surely - like saving the odd bit by a little
less water in the kettle or using the vacuum less - or going faster with it.
If you had conventional bulbs you would not have noticed the small current
flowing through the filamane to power the security switch electronics.
Would that be more or less power than the standby on a tv. Seems that there
is another way of saving power here. I hadn't realised that the power to run
a light sensitive switch would power up a CFL bulb.. I just wonder why the
public can't be advised of this problem, if you can call it that. I assumed
that it was a wiring fault.
Well, it is not actually powering it up is it - it is just flashing
occasionally. Look at it this way - an LED, constantly on and powered
from a small battery, the battery might last a day. The same LED and
battery designed to just flash and the battery would last for months.
The alternative could be lights left on and forgotten about.
The issue is not about the CFL Lamp - the issue is that you are needing to
power an electronic device - the security switch. Do you expect it to run on
fresh air? If you dig out the instructions it should tell you it consumes
something - perhaps in the order of 0.2 of a watt. It gets its 'neutral' to
complete its circuit through the electronics of the CFL - or the filament of
a bulb. The bulb would get immeasurably warm as a result - the CFL will give
an occasional flicker.
Before you get paranoid about your TV Standby - look at the spec. Modern
sets are very low - mine is only 0.8 of a watt - not that it gets left on
Bigger fish to fry as they say.
(Why don't people reduce the timer setting on their PIR Lights for example)
Ha ! Joy ! At last someone who understands the eco bollox about standby
modes, that is continuously thrust at us now ...
OTOH, has anyone looked at how much an LCD TV consumes when it's on,
compared to a modern CRT set ? And plasmas, well ... The backlighting for a
decent size LCD consumes over 100 watts on its own !
On Sat, 21 Feb 2009 01:14:34 -0000, Arfa Daily wrote:
The politicians that want TVs etc. not to have standby do not, yet again,
understand this: if TVs had only On and Off, many people would just mute
the sound for the odd half hour between shows - no standby at <1W would
become left on at 100W.
I don't use standby much on the TV but the satellite box is always switched
off if the interval is >15 min. as it's about 15W in 'standby'.
You don't understand Newton's Third Law of Motion?
It stems from old TV's. If you have a TV well over 10 years old,
it will have a standby of something like 5W - 10W, and depending
on how much you use it, you might find total standby consumption
exceeds the actual viewing consumption. Many countries have had
rules in place for many years now limiting standby power to < 1W,
and given TV's are manufactured for use in many different countries,
we all benefit from those rules in any new TV you buy today, even
when we don't actually have such a rule.
We still have problems with items designed for use only in this
(or only a few) countries, which are things like set top boxes.
They often don't significantly reduce consumption in standby
[email address is not usable -- followup in the newsgroup]
I can't see how total standby can exceed actual viewing consumption - this
sounds even more like eco bollox!
The solution is to check the manuals - it is always stated.
I guess you mean total standby if used for 18 hours a day versus viewing for
about 6 hours. Sorry I misunderstood you. (still seems unlikely though)
I guess most people switch off when going to bed ................ don't
No. Most people press the button on the remote. For everything.
Quite a few set top boxes etc. *require* to be left on standby, or they
don't get their updates for the EPG or firmware. And of course in the
case of Sky+ or V+ can't *upload* their viewing figures...
Some STB's etc use about the same energy on standby as in operation
Actual hours TV watched may be 2-5 hours.
So standby hours = 19 - 22 hours (if maximised by the user).
Ergo standby consumption can far exceed useful consumption.
Viewing say 4hrs in the evening @ 80W = 320Whrs. There are 20hrs left of
the day in standby, if that standby power is >16W then the set will use
more power in standby than it does for viewing.
As has already been pointed out modern kit has very low standby powers
(<1W) but older stuff could well have >16W.
I'm pretty sure that the likes of reputable companies like Pace and
Panasonic and so on, don't go out of their way to ignore their moral - if
not mandated in local law - responsibilities regarding energy useage,
particularly in the case of this green-driven and very contentious issue of
In many cases - set top boxes in particular being a good example - standby
mode is not just for the convenience of the lazy owner who can't get his
lardy arse beyond reaching for the remote control. Rather, it is masking
important 'housekeeping' issues such as maintaining the EPG, maintaining the
software revision, keeping the phone line modem alive, keeping the LNBs
powered for stability, and in the case of boxes with HDDs in them, retaining
the ability to do live rewind and so on.
Also, almost all modern consumer electronics products such as TV sets, STBs,
DVDs, DVDRs, HDDRs etc, all use switchmode power supplies, which often
employ a burst standby mode which can give misleading readings as to standby
power consumption, when it is measured on 'cheapo' consumer power meters.
The thing is with switchers, once they are running, they tend to be pretty
benign and reliable. Their big stress time is at cold startup, and is the
time that most spontaneously fail. Often, when they do, the failure is so
catastrophic as to render the power supply either uneconomic, or not safe to
repair - if you could even obtain some of the exotic OEM devices employed in
them (and no, typically, the manufacturers are of no help here). If this
happens, and the unit becomes just so much scrap, then all of your green
efforts will have been for nothing as the the unit will either find its way
to landfill, or have to have all the energy that you have saved, spent on
dismantling and recycling it.
This is where I have a problem with the way that green issues are being sold
to the general public. The politicians in their fervour to push this on us,
are only looking at one issue at a time, instead of employing joined-up
thinking. "Standby power consumption is bad ! Switch off when not in use !"
Well, not necessarily if you look at the bigger picture.
"CFLs are good and eco friendly ! Ban power gobbling incandescents !" Yes,
CFLs consume less energy than incandescents when in use, but this is the
*only* eco advantage that they have over traditional light bulbs. In all
other eco issues, they come out worse ...
It all adds up.
From a list the other week ...
TV: Toshiba 2500TB. 13.4W standby. 75W running. (12 year old).
TV: Panasonic TX-1. 5.8W and 57W (25? years old).
Video recorder: Panasonic. 8.1W and 16.5W (10 years old).
DVD player. Tesco. (8 months old) 8.5W continuous
Freeview box (Asda, 2 months old). 5.5W continuous
Freeview box (Aldi, 'Tevion' 18 months old). 10.3W continuous.
20" 'V7' PC LCD monitor, 21W dim, 42.5W bright.
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